import cadquery as cq
w0=cq.Workplane('XY',origin=(0,0,27))
r=w0.sketch().segment((-77,-100),(77,-100)).segment((77,-54)).arc((94,0),(77,54)).segment((77,100)).segment((-77,100)).segment((-77,54)).arc((-94,0),(-77,-54)).close().assemble().circle(21,mode='s').finalize().extrude(-54)